Telephone-receiver.



PATENTBD NOV. 6, 1906.

C. T. MASON.

' TELEPHONE RECEIVER.

APPLIOATION FILED MARJ. 1906.

INVENTOR ll-lllllllll W1 TNESSES Aizameyl.

Tu: NORRIS PETERS co.. WASNINCYON. D. c.

CHARLES T. MASON, or SUMTER, SOUTH CAROLINA, AssreNo-R roa'rmi SUMTERTELEPHONE MANUFACTURING CAROLINA, A CORPORATION.

COMPANY, OF SUMTER; SOUTH TELEPHONE-FIECE TVE R Specification of LettersPatent. v Application filed March '7, 1906. Serial No. 304.674.

Patented me. e, iota To all whom it may concern.-

Be it known that I, CHARLEs T. MASON, a citizen of the United States,residing at Sumter, in the county of Sumter and State of South Carolina,have invented new and useful Improvements in Telephone-Receivers, ofwhich the following is a specification.

This invention is a telephone-receiver having for its chief object toproduce a complete and operative receiver, the assembly, adjustment, andoperation of which are entirely independent of the hard-rubber orcomposition casing. The magnet structure is associated I with andconnected to the coils and diaphragm in such manner that these parts areindependent of the casing and are operated with or without the same. Aspecial feature of the invention is a metal cap, which screws on the cupand clamps the diaphragm to the front end thereof, the cup being firmlysecured to the magnet structure. The cap has the further feature that itprotects the diaphragm from punching with a lead-pencil or otherinstrument.

A form of the invention is illustrated in the accompanying drawings, inwhich Figure 1 is a sectional view showing the cap, the interior ormagnet structure, and the casing in separated condition. Fig. 2 is asectional view of the same parts assembled, the section being at a rightangle to that shown in Fig. 1. Fig. 3 is a plan view of the metal capwhich clamps the diaphragm to the cup.

Referring specifically to the drawings, a indicates the ear piece, whichscrews on the hard-rubber or composition casing is. The diaphragm isindicated at c, and it is clamped to a cup d by means of a metal cap I),which screws onto the rim of the cup. The cap B fits within the rabbetin the earpiece a, formed to receive it, and when assembled the cup (1fits within the front end of the casing is with its rim against the endof said casing, and the parts are all clamped together by thescrew-threaded engagement of the earpiece and the casing. Thepole-pieces e are fastened securely in a plate Z, which is secured tothe bottom of the cup by two screws 9, which also clamp the coils f inplace by extending through perforated ears formed on the end plates f ofthe coils. This allows the coils to be readily removed and replaced.

The pole-pieces are clamped onto the end of the horseshoe-magnet 'i bymeans of a bolt h, which also clamps the fiber-block m between the endsof the magnet; The cord terminals j are secured to the fiber-block byscrews j.

The plate Z encircles the pole-pieces e, and when the plate is screweddown to the bottom of the cup the lugs e on the edges of the pole-piecescome against the bottom of the cup. The pole-pieces are very tightlyfitted into said plate Z, and when the parts are screwed together thecup and the diaphragm and coils are rigidly mounted upon and se cured tothe magnet structure. This forms an operative receiver entirelyindependent of the casing. In fact the casing can be removed withoutaffecting in any manner the operation of the parts, the metal cap I)answering the purposes of an earpiece. Consequently the parts may beassembled and adjusted before they are put in the casing, and theyremain at adjustment independent of any manipulation of the casing.Consequently unscrewing or tampering with the earpiece at the hands ofinexperienced persons, will not affect the operation of the receiver.

The metal cap I) is preferably provided with a ring of holes p, thediameter of which ring is greater than that of the hole in the earpiece,so that the former lie beyond the latter, and punching the diaphragmwith a lead-pencil or the like is prevented and it is impossible toreach the diaphragm from the outside. However the cap may, if desired,be provided with a single hole opposite the hole in the earpiece, or thecap may have a single hole and the earpiece have a ring of holes,reversing the construction first mentioned.

The construction shown facilitates manufacture, test, and adjustment ofthe receiver and provides a construction proof against ordinarytampering after the telephone is set up.

I claim 1. In a telephone-receiver, the combination of a magnet havingpole-pieces, a cup at the front end of the magnet and through which thepole-pieces project, coils upon the pole-pieces, within the cup, acasing upon the front end of which the rim of the cup rests, a diaphragmupon the cup, a perforated cap screwed on the rim of the cup and underupon said plate, and screws extending through which the diaphragm isclamped, and an earthe end pieces of the coils and the plate into piecewhich is screwed onto the casing, over the bottom of the cup. the cupand cap. I In testimony whereof I have signed my 5 2. In atelephone-receiver, in combination, name to this specification in thepresence of I5 a on supported in the casing at the front end twosubscribing witnesses.

of t e magnet and through Which the pole- CHARLES T. MASON. piecesproject, a plate which fits in the bot- Witnesses: tom of the cup,around the pole-pieces, coils F. C. MANNING,

10 on the pole-pieces in the cup and mounted MURT HALL.

